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Building Tips and technical articles. => Building techniques => Topic started by: Dick Pacini on March 16, 2013, 07:18:55 PM
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A little background here; I have an Umland Coyote still in the bones. I got the fuselage assembled and motor mounts epoxied in. My intention is to run a 25 in the nose. I have LA 25's available but waited until the Brodak 25's were available. I grabbed two.
Unfortunately, the Coyote was designed for a 35 and the motor mounts are spaced for same. The nose of the coyote is unique in that it uses 1/4 triplers on each side, with appropriate cutouts for the engine and tank. Walter did an excellent job on the kit. I wanted to use aluminum crush plates and had to make some small ones that would fit in the recess already laser cut in the triplers. So, with those made and screwed down, I set the engine in place and thought I had it centered properly. There wasn't much meat to start with. I marked the holes and then drilled through the plates and into the maple mounts.
As luck would have it, both holes broke through the maple on one mount and through one hole on the other. I walked away for a couple of days and decided to figure a way to plug the open slots/holes on the side of the mounts. I took a piece of 1/2" square hardwood and cut a piece that would extend the exposed length of the mounts. Then, I set the piece on edge and split it corner to corner on my bandsaw. Now, I had two triangles, which I sanded smooth and relieved as required to fit snug against the motor mounts. Once fitted and epoxied in, they looked perfect and fixed the problem.
I have included pix which show the repair, the engine in place and the triplers prior to being shaped and hollowed. I regret not getting a shot of the mounts with the holes in the sides. I am going to pick up the pace on finishing this airplane.
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Nice recovery Dick!! The Coyote looks like a great airplane.
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Yes, things happen. Looks like you did a great fix to the problem.
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A very clever and effective fix! Way to go, and a repair jewel for the rest of us to remember.
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Just wondering here, and not to detract from the brilliant lateral thinking shown here, that if mounting pads are intended then why not simply have a wider bearer on the inside in the first place?
That or bring the bearers together a tad.
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Some of us never think of that. I too have done a kit build and then changed mind on engine of choice only to find the beares are no close enough together. Yes, a Dremel will take care of it if they were installed too close to begin with. We live and learn. H^^
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Just wondering here, and not to detract from the brilliant lateral thinking shown here, that if mounting pads are intended then why not simply have a wider bearer on the inside in the first place?
That or bring the bearers together a tad.
The fuselage was pre-slotted for the motor mounts and I didn't know the 25 had a narrower footprint than the old 35's. I already had the mounts epoxied in, so my options were limited. I haven't built a plane since 1974, so I am having to re-learn lots of technique. The next one will be better.
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A little time under a heat lamp will soften the epoxy and allow you to remove the bearers and make new ones.
Don